1. Field of the Invention
The invention is directed to a high density electrical connection system for terminating to a high density ribbon cable.
2. Description of the Prior Art
The development of new electrical cables in which a large number of wires are encapsulated in a flat insulating web has produced significant advantage in computers, telecommunication devices, and in electronics generally. These cables are manufactured with conductors formed as fine parallel wires, as small as 0.2 millimeter (mm) in diameter (0.008 inches) on 0.5 mm centerlines. These conductors may be used for transmitting electrical power or, in the alternative, electrical signals. Advantageously, then it should be appreciated that these high density cables produce a significantly smaller, and higher density package.
Along with the obvious advantages of size reduction and package density, such flat ribbon cables also present certain disadvantages. For example, with the conductors separated by only 0.5 mm, the common approach of insulation piercing technology is ruled out. Rather, an entirely new approach must be taken with such small wires, and small wire spacings. With such small packages, the conventional techniques of molding and stamping are also stretched to their limits in terms of tolerances.
Furthermore, such wire connectors are adapted for connection with pin headers on printed circuit boards. With the increased density of the wire connectors, it is often required to have special fixtures for wave soldering the pin headers to the printed circuit boards to prevent solder from wicking between and commoning adjacent posts. For example, if adjacent pins in the header are closer than 0.050 inches apart, special tooling is required to prevent solder wicking. Thus, it would be advantageous if the wire connector would dictate a pin header design which would not require such special fixtures.
While connector systems are known generally in the art for terminating ribbon cable conductors to further conductors, such systems are not suitable for use with such high density cables.
For example, U.S. Pat. No. 4,367,909 to Shatto, Jr., et al shows an electrical connector having housing parts with wire receiving grooves in which the cables reside for alignment with insulation displacement type electrical terminals. The terminals are also disposed in more than one row to stagger the positioning of the terminals, allowing the wire alignment grooves to be spaced further apart. Even with the staggered rows of electrical terminals, this type of electrical connection system is not capable for use with such high density systems.
In one attempt to accommodate high density ribbon cables, U.S. Pat. No. 4,747,787 to Siwinski, an electrical connection system positions terminals into three rows. The ends of the ribbon cable are stripped, and the conductors are formed to meet the terminal rows. Some of the conductors are maintained in the same plane as the ribbon cable, and these conductors are aligned with the center row of electrical terminals. Some of the bared conductors are bent upwardly to one side of the cable to meet the terminals in one outer row, while the remainder of the terminals are bent in the opposite direction to meet the remaining row of terminals. The wires are thereafter soldered to the terminals to electrically connect the two together. While the system bears utility for some applications, other such applications differ, for example, many applications require a solderless installation process.
An object of the present invention then is to provide an electrical connection system for interconnecting to high density ribbon cable as referenced above.
Another object of the invention is to provide an electrical connection system where the terminals of the system can be interconnected to the cable without the requirement of such processes as soldering.
Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.